Clinical trial of continuous adductor canal block with different concentrations of dexmedetomidine combined with ropivacaine on analgesia after TKA
Objective To observe the application effect and safety of continuous adductor canal block(ACB)with different doses of dexmedetomidine(DEX)combined with ropivacaine in postoperative analgesia of total knee arthroplasty(TKA).Methods Patients with TKA were enrolled as the research subjects and were divided into low-dose group,middle-dose group and high-dose group by the random number table method.At 10 min before induction of general anesthesia,all the groups were given 20 mL of 0.5%ropivacaine loading dose for ACB,placed nerve block indwelling catheter,and started ACB analgesia pump after the end of surgery.Low-dose group,middle-dose group and high-dose group were given 0.5,1.0 and 1.5 μg·kg-1 DEX+0.25%ropivacaine for a total of 100 mL,with a background dose of 4 mL·h-1and a control dose of 4 mL,and they locked for 30 min and continuously treated for 48 h.The surgical parameters and postoperative recovery quality of the two groups were compared.Visual analogue scale(VAS)was used to evaluate the pain status in resting state and motion state at 2,6,12,24 and 48 h after surgery.The number of effective compressions of self-controlled analgesia pump and the dosage of remedial analgesics at 48 h after surgery were counted and the safety evaluation was performed.Results No cases dropped out during treatment,and finally 30 cases were included in low-dose,middle-dose and high-dose groups,respectively.The first ambulation times in low-dose,middle-dose and high-dose groups were(54.22±8.37),(47.68±7.65)and(52.79±8.74)h;the time of active knee flexion 90° were(8.90±3.10),(7.20±2.70)and(8.60±2.40)d;the motion VAS scores were(3.86±0.59),(3.57±0.51)and(3.48±0.52)points at 48 h after surgery;the times of first analgesia pump compression within 48 h after surgery were(10.57±3.87),(12.45±3.63)and(13.36±3.56)h;the number of effective compressions of self-controlled analgesia pump were(6.11±2.18),(3.76±1.14)and(3.24±1.07)times;the remedial analgesia rates were 13.33%,0 and 0;at 6 h after surgery,quadriceps muscle strength scores were(4.81±0.21),(4.75±0.23)and(4.61±0.26)points,and the incidence rates of adverse drug reactions were 20.00%,6.67%and 6.67%,respectively.There were statistically significant differences in the above indicators between low-dose group and middle-dose group except for the incidence of adverse drug reactions(all P<0.05).There were statistical differences between low-dose group and high-dose group except for the incidence of adverse drug reactions(all P<0.05),but there were no statistical differences between middle-dose group and high-dose group(all P>0.05).Conclusion The use of 1.0 μg·kg-1DEX combined with ropivacaine for ACB in TKA patients can achieve good postoperative analgesia effect and it has small impact on muscle strength and has good safety,thus this dose can be used as a clinical recommended dose.
dexmedetomidinecontinuous adductor canal block of ropivacainetotal knee arthroplastypostoperative analgesiasafety